Latest news with #cellbiology
Daily Mail
21-07-2025
- Science
- Daily Mail
Scientists are BAFFLED after discovering a mysterious new structure hiding inside human cells
Scientists have discovered a mysterious new structure lurking inside every human cell. These tiny structures, dubbed hemifusomes, are just 200 to 400 nanometres in diameter. To put that into perspective, that's about 500 times thinner than a human hair. Scientists believe the structures play a critical role in helping our cells recycle and discard waste materials. Co-author Dr Seham Ebrahim, of the University of Virginia, says: 'It's exciting because finding something truly new inside cells is rare - and it gives us a whole new path to explore. 'This is like discovering a new recycling centre inside the cell. 'We think the hemifusome helps manage how cells package and process material, and when this goes wrong, it may contribute to diseases that affect many systems in the body.' In the future, the finding could help scientists to develop treatments for conditions such as Hermansky-Pudlak syndrome - a rare genetic disorder that can cause albinism, vision problems, and lung disease. Since hemifusomes are exceptionally small, the researchers needed extremely sensitive equipment to spot them. The team used a method called cryo-electron tomography, in which samples are rapidly frozen to around -150°C (-240°F) before being sliced very thinly. The scientists then took lots of photos with a powerful microscope which uses electrons instead of visible light. This allowed them to look at extremely small structures just as they would appear in a living cell by freezing them in time, rather than damaging the samples by trying to preserve them. Using this method, a team of researchers from the University of Virginia spotted structures which looked like two thin bubbles stuck together at the edges. The researchers believe hemifusomes produce vesicles - tiny sacs that act as 'mixing bowls', as well as making structures made of lots of these vesicles. Dr Ebrahim says: 'You can think of vesicles like little delivery trucks inside the cell. 'The hemifusome is like a loading dock where they connect and transfer cargo. It's a step in the process we didn't know existed.' By placing vesicles inside themselves, hemifusoles can store and combine different chemicals and waste products. Scientists think that some diseases might be caused when this process is disrupted By building vesicles, and even putting vesicles inside each other, the hemifusomes allow our cells to package and sort proteins or recycle parts of the cell. One thing that the researchers were surprised to find is that the layer which connects the hemifusome and the vesicles is much thinner than scientists previously thought possible. This 'hemifusion diaphragm' sticks to the two structures together but doesn't let their contents mix, like two water balloons that have melted together at the edges. Previously, scientists thought these types of structures would be too unstable to do anything useful in our cells. But in the hemifusome, the researchers spotted them playing a really important role in keeping our cells healthy. That discovery could have big implications for how we understand and treat diseases which interfere with our cells' recycling functions. Dr Ebrahim says: 'We're just beginning to understand how this new organelle fits into the bigger picture of cell health and disease. 'Now that we know hemifusomes exist, we can start asking how they behave in healthy cells and what happens when things go wrong. That could lead us to new strategies for treating complex genetic diseases. Cells in numbers Scientists believe the first known cells originated on Earth 3.8 billion years ago. The diameter in centimeters of most animal cells is 0.001 to 0.003, making them invisible to the naked eye. In 1665, British scientist Robert Hooke coined the term cell to describe the porous, grid-like structure he saw when viewing a thin slice of cork under a microscope. There are 200 different types of cells are in the human body. There are 24 hours in an animal cell cycle, the time from a cell's formation to when it splits in two to make more cells. A human red blood cells lives about 120 days. Each day, approximately 50 to 70 billion cells die in the human.
Yahoo
07-07-2025
- Health
- Yahoo
Whoa—Scientists Found a Part of Human Cells We Never Knew Existed
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Here's what you'll learn when you read this story: Hemifusomes are fused vesicles, or sacs of fluid, that were previously unknown to exist inside cells. They were discovered using cryo-electron tomography, which literally freezes them in time, and confirmed to be actual organelles and not just background noise. Because hemifusomes collect and recycle junk proteins, they could mean more effective treatments for diseases caused and aggravated by protein plaque buildup, such as Alzheimer's. Back in high school biology, most of us learned about the innards of a cell, or its organelles, from ribosomes to mitochondria to the endoplasmic reticulum, and probably had to identify them on our midterms. Now, an unexpected discovery will probably soon rewrite those textbooks. The hemifusome is the new organelle that high school students (much to their chagrin) will have to remember. Biophysicist Seham Ebrahim of the University of Virginia and her team of researchers were observing mammalian cells when they discovered hemifusomes, which previously eluded detection because they are even smaller than mitochondria and can easily blur or be mistaken for background noise. These nano-orbs, which look like they have, noses bear an uncanny resemblance to BB-8 or the profiles of certain Muppets. Pop culture references aside, their function of organizing, cleaning up, and recycling proteins could potentially unlock new treatments for genetic and neurodegenerative diseases. Hemifusomes consist of two vesicles, which are membrane sacs filled with liquid and formed by hemifusion, meaning that the smaller of the two is fused to the larger one like a hemisphere, almost as if its other half is missing. This occurs when the outer layers of two membranes merge first while the inner membrane layers stay open until a thin connection between them forms a new vesicle. The attached vesicles are sometimes found on the outside of the organelle and sometimes on the inside, and though where exactly these vesicles originate is still unknown, hemifusomes are thought to facilitate the formation of new vesicles that transport materials throughout the cell. This is probably how they take out cellular trash. Ebrahim used cryo-electron tomography, or cryo-ET, to observe and image hemifusomes. The cells, which were kept at cryogenic temperatures, were imaged in two dimensions using an electron microscope. Superfast cameras then took multiple photos of the frozen cells and their organelles. From these photos, single images were created using algorithms, upgrading the 2D images to 3D. 'Our observation of hemifusomes in four different cell lines originating from various species and tissues and frozen as close as possible to their native state suggests that they may be common components of the cell periphery in a wide range of cells and tissues,' she said in a study recently published in Nature Communications. Something else the researchers wanted to explore was what kind of relationship hemifusomes had with endosomes, which are vesicles that transport extracellular material into the cell via the process of endocytosis. The cell's plasma membrane will fold inward to surround matter, such as food molecules, in the surrounding fluid. These molecules are then taken in by the cell, whose plasma membrane pinches off to create an endosome that carries them into the cytoplasm. Endosomes can also form through the fusion of vesicles that already exist within the cell. Ebrahim traced the activity of endosomes and hemifusomes, but they did not appear to work together. What makes hemifusomes so important is how they collect and recycle junk proteins. Many studies have shown that the buildup of protein plaque in the brain can cause and aggravate neurodegenerative diseases such as dementia and Alzheimer's, and more understanding about how these organelles operate could lead to the development of treatments that work with them. 'Future research should focus on determining whether hemifusomes and compound hemifusomes are present in other cellular regions,' Ebrahim said, 'and on elucidating the molecular mechanisms underlying their formation, stability, and function, as well as their broader implications for cellular physiology and pathology.' You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Gizmodo
30-06-2025
- Health
- Gizmodo
Biologists Uncover Previously Unknown Structure Hiding Inside Human Cells
Even after decades of peering into cells, biologists are still finding surprises. In a twist, researchers at the University of Virginia and the National Institutes of Health uncovered a new organelle, dubbed the hemifusome. This tiny membrane-bound structure serves as a cellular recycling center and may hold the key to treating several genetic diseases. The research has been published in Nature Communications. 'This is like discovering a new recycling center inside the cell,' co-author Seham Ebrahim, a biophysicist at the University of Virginia, said in a statement. 'We think the hemifusome helps manage how cells package and process material, and when this process goes awry, it may contribute to diseases that affect many systems in the body.' Scientists had not previously identified the structure because it only appears when needed. But thanks to cryo-electron tomography—an imaging technique that flash-freezes cells and captures them in 3D and in near-atomic resolution—researchers were able to observe the ephemeral structure. The researchers say hemifusomes may aid in the formation of cellular vesicles, tiny sacs that shuttle and combine material throughout the cell. They might also help form other organelles composed of multiple vesicles, the study suggests. However, some evidence shows that hemifusomes do not participate in endocytosis, the traditional pathway by which cells engulf external material. 'You can think of vesicles like little delivery trucks inside the cell,' Ebrahim said in a statement. 'The hemifusome is like a loading dock where they connect and transfer cargo. It's a step in the process we didn't know existed.' Despite their fleeting nature, hemifusomes are not rare. They appear to be surprisingly common in certain parts of cells, particularly near the cell membrane. Still, scientists aren't exactly sure how or why hemifusomes form and then disappear. They're hoping to find that out—as well as understand what happens when hemifusomes fail to function properly. Problems with how cells handle cargo are at the root of many genetic disorders. 'This is just the beginning,' Ebrahim said in a statement. 'Now that we know hemifusomes exist, we can start asking how they behave in healthy cells and what happens when things go wrong. That could lead us to new strategies for treating complex genetic diseases.'
Geek Wire
12-06-2025
- Science
- Geek Wire
Seattle's Allen Institute launches ‘moonshot' to create new approach to cell biology research
A cross-section image of cells forming a hollow sphere, called a lumenoid. The colors mark different proteins expressed by the cells inside and outside of the sphere. (Allen Institute Image) Human cells, like the people they create, are dynamic and complex. And while researchers can create images and videos of how they move, organize and change their properties, it's hard to efficiently and accurately describe all that's happening. So a 75-person team at Seattle nonprofit Allen Institute is embarking on a 10-year project called CellScapes to devise a new language using mathematics to capture these essential processes. 'This is a new way of approaching very fundamental cell biology,' Ru Gunawardane, executive director and vice president of the Allen Institute for Cell Science, told GeekWire. 'We want to combine math and biophysical modeling, which are things that people are doing right now, but in a siloed way in very different systems.' Ru Gunawardane, executive director and vice president of the Allen Institute for Cell Science. (Allen Institute Photo) The Allen Institute was founded more than 20 years ago by the late Microsoft co-founder Paul Allen and his sister Jody Allen to dive into challenging problems in the biosciences. Previous efforts at multiple institutions have created numerical systems for understanding biological processes. That includes BayesSpace, a computational tool that produces data on gene expression in mixed cell types that developed researchers at the Fred Hutch Cancer Center. The Allen Institute has engineered modeling for organelles, which are the various machines packed inside cells that make proteins, produce energy and perform other key operations. 'The exciting thing is that we are trying … to bring different disciplines together,' Gunawardane said, 'because data is everywhere — but how do you make sense out of that data?' The CellScapes researchers are working with human stem cells, which are cells that don't yet have a set identity as, say, a skin or liver cell. The hope is through analysis and experimentation they'll devise mathematics that describe the cell's behavior, ultimately allowing them to predict and manipulate what the cells do. A primary goal would be to use these tools to unravel mysteries such as the intermediate steps to developing cancer, and ultimately discover new cell therapies. 'It's a lot like astronomy and going from 'which planet is that dot in the sky' to 'what are the laws of motion that describe all moving objects?'' said Wallace Marshall, professor of biochemistry and biophysics at the University of California, San Francisco, and a CellScapes advisor, in a statement. The Allen Institute seen from Dexter Yard. (GeekWire File Photo / Charlotte Schubert) The Allen Institute will make its data and innovations in the space publicly available, Gunawardane said, and expects to collaborate with researchers at outside institutions. The research team includes software engineers, computational biologists, program managers and others. There is no set budget for the decade-long effort, and the CellScapes team is simultaneously pursuing three projects that are part of the broader initiative. The effort already has a scientific paper accepted by the journal Nature that will be published in coming months. It's an exciting time, Gunawardane said. 'I also feel a huge responsibility,' she said, 'because Paul [Allen] is not alive anymore, but our work is his legacy, and he asked us to break the code of the cell. And in a way, the code is very complicated — it's more like a program, the cellular program. 'So I feel like we are now actually at the brink,' she said, 'of knowing maybe how to approach that.'
